The fluid suctioned from human body needs to be stored, filtered and gas-discharged before it is injected back into the body to achieve the purpose of curing diseases during the treatments of certain diseases. For example, intracranial hematoma aspiration is used in the present treatment of cerebral hemorrhage, and the hematoma is aspirated after being cut and pulverized by an aspirator in this technique. The aspirator is connected to a balance lavage device under the continuous negative pressure at the same time. The pulverized and aspirated hematoma is filtered and then injected back into the skull to remain the volume of hematoma cavity unchanged for the purpose of removing hematoma.
A patent application entitled “A Hematoma Evacuator” has been applied by the applicant on Apr. 25, 2010. In technology of the patent, filter and gas-discharging apparatuses are configured in separated configurations to store, filter and gas-discharge the sucked working fluid. Such design may however cause gas retention in the filter easily, which gas within the hematoma evacuator cannot be discharged by the gas-discharging apparatus and thereby may increase operation risk.